Method for the preparation of vanadium-antimony-oxide based oxidation and ammoxidation catalysts using non-aqueous media

ABSTRACT

Vanadium antimony oxide catalysts useful for the selective oxidation and ammoxidation of paraffins, olefins, and aromatic compounds are manufactured in a process comprising (i) forming a catalyst precursor slurry comprising a vanadium containing compound and an antimony containing compound in a liquid solvent medium which comprises an organic solvent, and (ii) recovering a vanadium antimony oxide from the slurry by drying the slurry in order to remove water and organic solvent.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to vanadium antimony oxide catalysts forthe selective oxidation and ammoxidation of paraffins, olefins, andaromatic compounds. More specifically, the invention relates to a slurrypreparation of vanadium antimony oxide based catalysts in a liquidsolvent medium comprising an organic solvent.

[0003] 2. Description of the Prior Art

[0004] Commercial processes for the production of acrylonitrile employpropylene as a feedstock. However, because of the price differentialbetween propylene and propane, an economic incentive exists for thedevelopment of a commercial process for the ammoxidation of propane toacrylonitrile. The development of such a process depends upon a viablecatalyst useful for the conversion of propane to acrylonitrile.

[0005] Catalyst comprising the oxides of vanadium, antimony and optionalpromoter elements (referred to herein as vanadium antimony oxidecatalysts) useful in the ammoxidation of propane to acrylonitrile alongwith various methods of making such catalysts are taught in thefollowing U.S. Pat. Nos. 5,994,259; 5,866,502; 5,498,588; 5,332,855;5,258,543; 5,214,016; 5,008,427; 4,788,317; 4,784,979; 4,746,641;3,860,534; and 3,681,421. The preparation of vanadium antimony typecatalysts disclosed in these patents all react a slurry of the vanadiumand antimony source compounds in a wholly aqueous medium. U.S. Pat. No.6,083,869, vanadium and antimony source compounds are dissolved in asaturated alcohol or a mixture of saturated alcohol and water, and thencontacted with an ammonium salt in order to precipitate the vanadiumantimony oxide.

SUMMARY OF THE INVENTION

[0006] Then invention relates to vanadium antimony oxide catalystshaving lower particle densities. Specifically, the present invention isdirected the process for making such catalyst wherein the vanadiumantimony oxide catalyst comprises vanadium, antimony, at least one oftin, titanium, iron, chromium and gallium, and optionally at least oneelement selected from the group consisting of lithium, magnesium,sodium, calcium, strontium, barium, cobalt, nickel, zinc, germanium,niobium, zirconium, molybdenum, tungsten, copper, tellurium, tantalum,selenium, bismuth, cerium, indium, arsenic, boron, aluminum, andmanganese, wherein the relative ratios of these elements are representedby the following general formula:

V₁Sb_(m)A_(a)D_(d)O_(x)

[0007] wherein A is at least one of Ti, Sn, Fe, Cr, and Ga.

[0008] D when present is at least one of Li, Mg, Ca, Sr, Ba, Co, Ni, Zn,Ge, Nb,

[0009] Zr, Mo, W, Cu, Te, Ta, Se, Bi, Ce, In, As, B, Al, and Mn,

[0010] m is between about 0.5 to about 10

[0011] a is between about 0 to about 10

[0012] d is 0 to about 10

[0013] and x is determined by the oxidation state of the cationspresent,

[0014] and wherein the process comprises (i) forming a catalystprecursor slurry comprising a vanadium containing compound and anantimony containing compound in a liquid solvent medium which comprisesan organic solvent, and (ii) recovering a vanadium antimony oxide fromthe slurry by drying the slurry in order to remove water and organicsolvent.

[0015] Further embodiments of present invention are directed to vanadiumantimony oxide catalyst produced by the process described above as wellas a process for the manufacture of acrylonitrile from a hydrocarbonselected from the group consisting of propylene, propane and mixturesthereof comprising reacting the hydrocarbon with ammonia and oxygen inthe presence of such vanadium antimony oxide catalyst.

DETAILED DESCRIPTION OF THE INVENTION

[0016] The instant invention relates to vanadium antimony oxidecatalysts prepared in a process utilizing a liquid solvent medium whichcomprises an organic solvent. Prior art slurry preparation methods in awholly aqueous medium typically produce catalysts having particledensities greater than 1 g/cm³. The method of the instant inventionproduces a vanadium antimony oxide based catalysts having particledensities of approximately 1 g/cm³. Among the benefits derived from themanufacture of a vanadium-antimony-oxide based catalyst having lowerparticle density than catalysts prepared by prior art wholly aqueouspreparation methods are:

[0017] (1) reducing the size (and therefor the capital cost) of acommercial vanadium antimony oxide catalyst charge for reactors in aprocess for the ammoxidation of propane to acrylonitrile,

[0018] (2) a vanadium antimony oxide catalyst particle density moresuited for operation in commercial fluid-bed reactors, and

[0019] (3) since a 1 g/cm³ particle density is similar to the particledensities of commercial catalysts used in the ammoxidation of propyleneto acrylonitrile, the vanadium antimony oxide catalysts of the instantinvention provides a catalyst that is operationally suitable to retrofitan existing propylene ammoxidation reactor for other applications, forexample, the ammoxidation of propane to acrylonitrile.

[0020] The vanadium antimony catalysts prepared as described herein alsoexhibit enhanced activity and productivity to useful products comparedto catalysts produced by prior art wholly aqueous preparation methods.

Catalyst Composition

[0021] The vanadium antimony oxide catalysts described herein comprisevanadium, antimony, at least one of tin, titanium, iron, chromium andgallium, and optionally at least one element selected from the groupconsisting of lithium, magnesium, sodium, calcium, strontium, barium,cobalt, nickel, zinc, germanium, niobium, zirconium, molybdenum,tungsten, copper, tellurium, tantalum, selenium, bismuth, cerium,indium, arsenic, boron, aluminum, and manganese, wherein the relativeratios of these elements are represented by the following generalformula:

V₁Sb_(m)A_(a)D_(d)O_(x)

[0022] wherein A is at least one of Ti, Sn, Fe, Cr, and Ga.

[0023] D when present is at least one of Li, Mg, Ca, Sr, Ba, Co, Ni, Zn,Ge, Nb,

[0024] Zr, Mo, W, Cu, Te, Ta, Se, Bi, Ce, In, As, B, Al, and Mn,

[0025] 0.5≦m≦10,

[0026] 0<a≦10,

[0027] 0≦d≦10, and

[0028] x is determined by the oxidation state of the cations present.

[0029] A preferred catalyst formulation, when applied to a process ofmanufacturing acrylonitrile or methacrylonitrile by catalytic reactionin the vapor phase of a paraffin selected from propane and isobutanewith molecular oxygen and ammonia by catalytic contact of the reactantsin a reaction zone, comprises vanadium, antimony, iron, at least one oftin, titanium, chromium and gallium, and at least one other promoterelement selected from the group consisting of lithium, magnesium,sodium, calcium, strontium, barium, cobalt, chromium, gallium, nickel,zinc, germanium, zirconium, tantalum, bismuth, cerium, indium, boron,aluminum, and manganese, optionally one or more of molybdenum, tungstenand niobium, and optionally one or more of arsenic, tellurium andselenium, wherein the relative proportions of these elements arerepresented by the following formula:

V₁Sb_(b)A_(c)Fe_(d)D_(e)Q_(f)R_(g)O_(x)

[0030] where

[0031] A is at least one of Ti, Sn, Cr, and Ga

[0032] D is at least one of Li, Mg, Ca, Sr, Ba, Co, Ni, Zn, Ge, Zr, Cu,Ta, Bi,

[0033] Ce, In, B, Al and Mn

[0034] Q is selected from the group consisting of Mo, W, Nb,

[0035] R is selected from the group consisting of As, Te, Se, and

[0036] 0.8≦b≦4,

[0037] 0.01≦c≦2,

[0038] 0.01≦d≦2,

[0039] 0≦e≦2,

[0040] 0≦f<0.01 and more preferably 0<f<0.0045,

[0041] 0≦g<0.1, and

[0042] x is determined by the oxidation state of the cations present.

[0043] In the above-described catalysts preferably “A” is both Sn andTi. Also a preferred catalyst composition is when Q is Mo and R is As.

[0044] The above-described catalysts may be unsupported or supported onany suitable carrier. Examples of suitable carriers are silica, alumina,silica alumina, zirconia and the like.

[0045] Representative catalyst formulations made by the process of theinstant invention include:

VSb_(1.5)Sn_(0.2)Ox

VSb₂Ti_(0.5)Ox

VSb_(1.4)Sn_(0.1)Fe_(0.2)Ox

VSb₅Cu₂Ox

VSb₂Cr_(0.2)Ga_(0.5)Ox

VSb₃Sn₂Fe_(0.6)Mo_(0.05)Ox

VSb₂Mg_(0.5)B₁Ox

VSb₆Co₁Cr_(0.6)Cu_(0.5)Ox

VSb_(1.5)Ti_(0.3)Li_(0.5)Ox

VSb_(1.7)Mn_(0.6)Mo_(0.1)Ox

VSb₈Ti₅Cr₁Cu_(0.5)Ox

Catalyst Preparation

[0046] In the practice of the instant invention, the production of thevanadium antimony oxide based catalysts described herein begins with thepreparation of a catalyst precursor dispersion, solution,, sol, orslurry comprising vanadium, antimony and optionally other promoterelements, referred to herein as the “catalyst precursor slurry”. Theslurry is prepared using a liquid solvent medium which comprises anorganic solvent. The slurry is then dried in order to remove the waterand the solvent and to yield the catalyst precursor. The catalystprecursor is then calcined to yield the finished catalyst.

[0047] The hallmark of the instant invention is the use of a liquidsolvent medium which comprises an organic solvent, in whole or in part,in the preparation of catalyst precursor slurry. The liquid solventmedium consists of up to 100 wt % of an organic solvent. Preferred is 10to 100 wt % of an organic solvent, more preferred is 50 to 100 wt %, andmost preferred is 80 to 100 wt %. The organic solvent can be added atany time in the catalyst preparation prior to the drying of the catalystprecursor slurry to form the catalyst precursor. The organic solvent maycomprise any organic compound or mixtures of organic compounds that is aliquid under the conditions used to prepare the vanadium-antimony-oxidebased catalyst. Examples of suitable organic solvents are hydrocarbons,or functionalized organic compounds such as alcohols, nitrites,carboxylic acids, amines, and sulfides. Also suitable are organiccompounds containing any combination of chemical functionalities. Ingeneral the non-aqueous solvent medium replaces the wholly aqueousmediums employed in most prior art vanadium antimony oxide catalystpreparations.

[0048] The general method used to prepare the catalyst, or morespecifically the catalyst precursor slurry, is not critical. Thisvanadium antimony oxide catalyst precursor slurry can be prepared by anymethod known in the art. Source compound for the vanadium, antimony andpromoter elements are as described below.

[0049] A particularly effective method of preparation of the catalystprecursor slurry is is disclosed in U.S. Pat. No. 5,866,502. This methodcomprises heating an aqueous mixture comprising water soluble vanadates(e.g. VO₄ ⁻³, VO₃ ⁻¹, V₂O₅) and Sb₂O₃ and, optionally, at least onecompound comprising a promoter element to a temperature between 110° C.and 250° C. under autogenous pressure with agitation for a timesufficient to allow at least the slightly water soluble vanadates andSb₂O₃ to react to form the catalyst precursor slurry.

[0050] The hydrothermal reaction of the metal oxides in the aqueoussolution is continued for a time period sufficient for the metal oxidesto suitably react to form the catalyst precursor. The required reactiontime is ultimately determined by the catalytic and physical propertiesof the final material obtained after calcination. Typically, thereaction is continued for between 0.5 to 100 hrs, preferably from 1 to50 hrs, especially preferred being 1 to 10 hrs. It has been observedthat shorter reaction times are required as one increases thetemperature employed during the catalyst precursor formation.

[0051] An alternative method of preparation of the catalyst precursorslurry is the so-called “peroxide method” disclosed in U.S. Pat. Nos.4,784,979 and 4,879,264. Specifically according to U.S. Pat. No.4,784,979, the catalyst precursor slurry is prepared by first preparinga monoperoxovanadium ion, VO(O₂)⁺, by reacting a vanadium compound withan aqueous hydrogen peroxide (H₂O₂) solution, and then reacting themonoperoxovanadium ion, VO(O₂)⁺, while in aqueous solution, with anantimony compound which contains Sb having a valence of 3, therebyreducing the average valence of the vanadium to less than 5 andoxidizing antimony to a valence state of 5. At least a portion of theSb⁺³ is so reduced, not necessarily all.

[0052] The vanadium source (i.e. the vanadium compound or vanadiumcontaining compound, as used herein) can be an inorganic or an organiccompound of vanadium, but is usually an inorganic compound. The vanadiumin the compound can have any initial valence. A partial list of suchcompounds includes any oxide of vanadium, such as V₂O₅, V₇O₁₃, VO, VO₂,V₂O₃, V₃O₇, etc.; any vanadium oxyhalide such VOCl₃, VOCl₂, (VO₂)Cl,VOCl, VOBr, VOBr₂, VOBr₃ ; any vanadium halide such as VF₃, VBr₃, VCl₂,VCl₃, VCl₄, VF₅; vanadyl sulfate; meta-vanadic acid; pyro-vanadic acid.

[0053] For the peroxide method, the vanadium compound usually used inthe reaction with H₂O₂ is one of the oxides. Because of availability andcost, V₂O₅ is often the compound that is chosen to react with thehydrogen peroxide.

[0054] The antimony source (i.e. the antimony compound or antimonycontaining compound, as used herein) can be an organic or an inorganiccompound of antimony. A partial list of such compounds includes any ofthe following types of compounds containing antimony having a valence of3: any such antimony oxide such as Sb₂O₃ and Sb₂O₄; SbOCl; any suchantimony halide such as SbBr₃, SbCl₃, SbF₃ and Sbl₃. The preferredantimony source in these preparations is Sb₂O₃

[0055] After the vanadium and antimony reaction has taken place,compounds comprising promoter elements may be added. These includescompounds of elements such as Ti, Sn, Fe, Cu, Mg, Mo, As, Li, Ca, Sr,Ba, Co, Ni, Zn, Ge, Nb, Zr, W, Te, Ta, Se, Bi, Ce, In, B, and Mn.Examples of sources of the metal promoters include nitrates, acetates,hydroxides, oxides, ammonium ion complexes, and carbonyls. A preferredpromoter is iron derived from an iron containing compound (e.g. Fe₂O₃)having a BET surface area of greater than about 120 m²/gram. For ironpromoted catalysts, the atomic ratio of iron to vanadium is preferablygreater than 0.2. For the peroxide prep described above, compounds ofsome elements such as Ti that form peroxo compounds can also be addedbefore or with the addition of the H₂O₂, but are usually mostconveniently added after the vanadium and antimony compounds havereacted. Alternatively, promoter elements may be added in sol form.Alternatively, promoter elements can be added prior to the reaction ofthe vanadium and antimony reaction as described in U.S. Pat. No.5,866,502 or promoter elements can be added by impregnation after dryingthe catalyst precursor slurry to remove water. The addition of promoterelements to the vanadium antimony oxide catalyst precursor slurry ordried catalyst precursor can be achieved by known methods in the artsuch as ion-exchange, solvo thermal treatment, and impregnation.

[0056] An additional alternative is to add promoter elements in solform. For example, U.S. Pat. No. 6,087,524 discloses the preparation oftin promoted vanadium antimony oxide catalysts using tin sols (made fromSnO₂.nH₂O) wherein the tin sol was dispersed in a quaternary ammoniumhydroxide. Additionally, a quaternary ammonium hydroxide (e.g.tetramethyl ammonium hydroxide or tetraethyl ammonium hydroxide can beadded to the catalyst slurry by itself in order to improve attritionresistance of the final catalyst. The quaternary ammonium hydroxide isadded such that the molar ratio of added QAH per gram of finishedcatalyst is between about 0.001 and about 10, preferably between about0.005 and about 0.5.

[0057] The catalyst can be supported on any suitable carrier. Examplesof such carriers are silica, alumina, silica-alumina, and the like. Aparticularly attrition resistant form of the catalyst contains silica,added as silica sol. Various types of silica sol, with particle sizes ofabout 5 to about 100 nanometers, can be used. The silica sol may beadded to the catalyst precursor slurry at any time prior to drying thecatalyst precursor slurry to form the catalyst precursor. Usually, thesecatalytic grade silica sols have low alkali metal content, and arestabilized by ammonia. Ion exchange with resins in acid or ammoniumforms can also be used to remove excess alkali or alkaline earth ionsfrom the silica.

[0058] The vanadium antimony catalyst described herein is recovered fromthe catalyst precursor slurry by drying. After making the catalystprecursor slurry as described above the precursor slurry is dried toremove water and solvent to yield a catalyst precursor which is thencalcined to produce the finished catalyst. Optionally, the catalystprecursor slurry may first be concentrated by heating the catalystprecursor slurry in order to evaporate residual quantities of waterand/or solvent. These heat treatments can be conducted as separateoperations in multiple pieces of equipment or they can be conducted insingle piece of equipment wherein the temperature is increased stepwiseor continuously over time. In the preparation of a fixed bed catalyst,the catalyst precursor slurry is typically dried by heating at anelevated temperature and then shaped (e.g. extruded, pellitized, etc.)to the desired fixed bed catalyst size and configuration. In thepreparation of fluid bed catalysts, the catalyst precursor slurry istypically spray dried to yield microspheroidal catalyst particles havingparticle diameters in the range from 10 to 200 microns. Unlike U.S. Pat.No. 6,083,869, the promoted vanadium antimony oxide formed during thepreparation of the catalyst is not contacted with an ammonium salt toyield a precipitate which is then recovered by filtration.

[0059] After the catalyst is dried and shaped into its fixed or fluidbed form, the catalyst is subjected to a high temperature heat treatmentor calcination in air or an oxygen enriched environment (i.e. a gaseousenvironment or atmosphere having a greater oxygen (O₂) content thanair). The high temperature heat treatment or calcination is conducted ata temperature of at least 600° C., preferably above 750° C. For vanadiumantimony oxide catalysts used for the ammoxidation of propane a hightemperature heat treatment or calcination at a temperature of at least780° C. is preferred. The high temperature heat treatment or calcinationtemperatures can be as high as 1200° C. Preferably the high temperatureheat treatment or calcination is conducted at a temperature in the rangeof about 790° C. to about 1050° C.

[0060] Optionally, as disclosed in U.S. Pat. Nos. 5,675,057 and5,696,047, the catalyst may be further heat treated at an effectivetemperature that is at least 500° C. and at least 50° C. below said hightemperature heat treatment calcination temperature.

[0061] The calcining step described above activates the catalyst to asignificant degree, optionally the catalyst may be contacted with analcohol (hydroxy compound) to further activate the catalyst. Thecatalyst may optionally be washed at any one or more points in theprocedure using the methods disclosed in U.S. Pat. Nos. 3,860,534 and/or5,094,989. Specifically, the catalyst can be washed after calcination bycontacting said calcined catalyst with a hydroxy compound in liquid form(usually having no carbon-to-carbon unsaturation) selected from (1)cyclohexanol, (2) cyclopentanol, (3) a monohydroxy, acyclic hydrocarbonhaving 1-8 C atoms, usually 1-10 C atoms, and (4) a dihydroxy, acyclichydrocarbon having 2-4 carbon atoms, and separating as a liquid saidcompound from said catalyst insofar as it is present beyond the amountwetting said catalyst, and thereafter drying said catalyst. Especiallyuseful hydroxy compounds are the monohydroxy, acyclic hydrocarbonshaving 1 to 8 carbon atoms, and the dihydroxy, acyclic hydrocarbonshaving 2 to 4 carbon atoms. Most useful are the monohydroxy, acyclichydrocarbons having 1 to 4 carbon atoms, especially isobutanol.

Processes

[0062] In another aspect of the present invention, there is provided aprocess for making an α,β unsaturated mononitrile selected fromacrylonitrile and methacrylonitrile, by catalytic reaction in the vaporphase of a paraffin selected from propane and isobutane with molecularoxygen and ammonia and optionally a gaseous diluent, by catalyticcontact of the foregoing reactants in a reaction zone with a catalyst,the feed to said reaction zone containing a mole ratio of said paraffinto NH₃ in the range of 2.5 to 16 and a mole ratio of said paraffin to O₂in the range from 1 to 10, said catalyst having an empirical compositiondescribed above, said catalyst having been made by a method describedabove. The reaction temperature range can vary from 350° C. to 700° C.but is usually between 430° C. and 520° C. The average contact time canbe from 0.01 to 10 seconds but is usually between 0.02 and 10 secondsand more preferably between 0.1 to 5 seconds. The pressure in thereaction zone is usually no more than 75 psia, but is preferably no morethan 50 psia.

[0063] The catalyst may also be used in the ammoxidation ofmethylpyridine and mxylene to cyanopyridine and isophthalonitrile or theoxidation of o-xylene to phthalic anhydride. The mole ratios of ammoniato methylpyridine and O₂ to methylpyridine are 1 to 5 and 1 to 10,respectively. The mole ratios of ammonia to m-xylene and O₂ to m-xyleneare 1 to 5 and 1 to 10, respectively. In the phthalic anhydridereaction, the ratio of O₂ to o-xylene may range from 1 to 10.

[0064] The catalyst prepared by the process of the present invention mayalso be utilized in the ammoxidation of propylene or isobutene withammonia and oxygen to produce acrylonitrile or methacrylonitrile. Themole ratio of ammonia to olefin may range from 1 to 5 and the mole ratioof O₂ to olefin may range from 1 to 10 in this reaction underconventional temperatures and conditions well known in the art.

[0065] The catalyst and processes described herein may be employed inany suitable reactor including fixed-bed, fluid-bed, and transport-bedreactors.

SPECIFIC EMBODIMENTS

[0066] For purposes of illustration only, the following examples are setforth to describe the process of the present invention.

Catalyst Preparation Example 1

[0067] A catalyst having the composition VSb₁ ₆Fe₀ ₆Mo₀ ₀₀₂₂O_(x) wasprepared by adding 9.109 of V₂O₅ along with 30 g of 30 wt % H₂O₂ (inwater) to 1000 ml of acetonitrile. Six additional aliquots of 30 g of 30wt % H₂O₂ (in water) were added over a period of 1.5 hours whereupon themixture had the appearance of a dark green sol. 23.32 g of Sb₂O₃ wereadded and the mixture was heated to 70° C. with stirring for about 5hours. 4.79 g of Fe₂O₃ powder were added and the mixture was heated to70° C. with stirring for an additional 5 hours. The resulting mixturewas cooled to room temperature and the liquid was removed from themixture by decanting. The solid was heated at 120° C. then at 325° C.for 3 hours and 650° C. for 2 hours. The solid was ground and sieved andthe 20 to 35 mesh particle size collected. These were then heat treatedat 820° C. for 3 hours, cooled to room temperature then washed withisobutanol and dried at 120° C. 2.93 g of the washed catalyst wastreated with an aqueous solution of ammonium heptamolybdate to give aMo/V ratio for the catalyst of 0.002/1. The treated catalyst was driedat 120° C. then heat treated at 325° C. for 3 hours and then at 500° C.for 3 hours.

Comparative Example A

[0068] A catalyst having the composition VSb₁ ₆Sn₀ ₀₅Ti₀ ₅Fe₀₄₅Mo_(0.0025)O_(x) was prepared by using the prior art peroxide methoddisclosed in U.S. Pat. Nos. 4,784,979 and 4,879,264. Essentially thispreparation was similar to the preparation of Example 1, except thatwater and tetramethyl ammonium hydroxide were the only solvents used toprepare the catalyst.

Catalyst Testing

[0069] The catalysts prepared above were tested for the ammoxidation ofpropane using a fixed-bed micro-reactor made of 0.25 inch O.D. titaniumtubing immersed in a temperature controlled molten salt bath. The molarratios of the feed compositions, reaction temperatures and contact timesfor the tests are listed in Table 2 below. Product analysis was donewith two gas chromatographs. One was fitted with a packed Carbowax onCarbopak column to determine nitriles in liquids collected in anice-cooled oxalic acid scrubber. The other was fitted with molecularsieve and is silicone oil columns for analysis of fixed gases and lighthydrocarbons in the feed and effluent gas streams. Reaction parametersare summarized in Table 1. The results tests are summarized in Table 2.TABLE 1 Run Conditions Feed Ratios WWH Temperature Pressure C₃H₈ NH₃ O₂N₂ Example 1 1.63 480° C. 15 psig 3 0.8 2 2 Comparative 1.09 480° C. 15psig 3 0.8 2 2 Example A

[0070] TABLE 2 Propane Catalyst Conver- Selectivities (%) Density sionUseful Produc- (g/cc) (%) AN Products CO CO₂ tivity Example 1 1.0 19 5875 14 11 0.216 Comparative 2.4 20 59 76 14 10 0.155 Example A

[0071] The results shown in Table 2 illustrate that the catalystprepared by the method of the instant invention (Example 1) hascomparable performance to the catalyst made by the prior art method(Comparative Example A) for the ammoxidation of propane. However, theCatalyst of Example 1 has significantly lower density than the catalystprepared by the prior art method (Comparative Example A). As statedearlier, lower catalyst density means that the catalyst of the inventionis more suitable for use in a commercial fluid-bed reactors than higherdensity catalyst prepared by the prior art methods. The catalyst of theinvention (Example 1) also has significantly higher productivitycompared to the catalyst made by the prior art method (ComparativeExample A).

[0072] It is to be understood that the subject invention is not to belimited by the exact description set forth in the examples herein. Thesehave been provided merely to demonstrate the operability of theinvention herein described. The selection of catalysts, metal sources,carbon supports, concentrations, contact times, solids loadings,feedstocks, reaction conditions, and products can be determined from thetotal specification disclosure herein disclosed and described, withoutdeparting from the spirit of the invention and the scope of theinvention, including modifications and variations, that fall within theboundaries of the attached claims.

That which is claimed is:
 1. A process for the preparation of a vanadiumantimony oxide catalyst comprising vanadium, antimony, at least one oftin, titanium, iron, chromium and gallium, and optionally at least oneelement selected from the group consisting of lithium, magnesium,sodium, calcium, strontium, barium, cobalt, nickel, zinc, germanium,niobium, zirconium, molybdenum, tungsten, copper, tellurium, tantalum,selenium, bismuth, cerium, indium, arsenic, boron, aluminum, andmanganese, wherein the relative ratios of these elements are representedby the following general formula: V₁Sb_(m)A_(a)D_(d)O_(x) wherein A isat least one of Ti, Sn, Fe, Cr, and Ga. D when present is at least oneof Li, Mg, Ca, Sr, Ba, Co, Ni, Zn, Ge, Nb, Zr, Mo, W, Cu, Te, Ta, Se,Bi, Ce, In, As, B, and Mn, m is between about 0.5 to about 10 a isbetween about 0 to about 10 d is 0 to about 10, and x is determined bythe oxidation state of the cations present, wherein the processcomprises (i) forming a catalyst precursor slurry comprising a vanadiumcontaining compound and an antimony containing compound in a liquidsolvent medium which comprises an organic solvent, and (ii) recovering avanadium antimony oxide from the slurry by drying the slurry in order toremove water and organic solvent.
 2. The process of claim 1 wherein theliquid solvent medium comprises 10 to 100 wt % organic solvent.
 3. Theprocess of claim 1 wherein the liquid solvent medium comprises 50 to 100wt % organic solvent.
 4. The process of claim 1 wherein the liquidsolvent medium comprises 80 to 100 wt % organic solvent.
 5. The processof claim 1 wherein the organic solvent comprises at least one organiccompound selected from the group, consisting of alcohols, nitrites,carboxylic acids, amines, and sulfides.
 6. The process of claim 1,wherein the catalyst comprises vanadium, antimony, iron, at least one oftin, titanium, chromium and gallium, and at least one other promoterelement selected from the group consisting of lithium, magnesium,sodium, calcium, strontium, barium, cobalt, chromium, gallium, nickel,zinc, germanium, zirconium, tantalum, bismuth, cerium, indium, boron,aluminum, and manganese, optionally one or more of molybdenum, tungstenand niobium, and optionally one or more of arsenic, tellurium andselenium, wherein the relative proportions of these elements arerepresented by the following formula:V₁Sb_(b)A_(c)Fe_(d)D_(e)Q_(f)R_(g)O_(x) where A is at least one of Ti,Sn, Cr, and Ga D is at least one of Li, Mg, Ca, Sr, Ba, Co, Ni, Zn, Ge,Zr, Cu, Ta, Bi, Ce, In, B, Al and Mn Q is selected from the groupconsisting of Mo, W, Nb, R is selected from the group consisting of As,Te, Se, and 0.8≦b≦4, 0.01≦c≦2, 0.01≦d≦2, 0≦e≦2, 0≦f<0.01, 0≦g<0.1, and xis determined by the oxidation state of the cations present.
 7. Avanadium antimony oxide catalyst comprising vanadium, antimony, at leastone of tin, titanium, iron, chromium and gallium, and optionally atleast one element selected from the group consisting of lithium,magnesium, sodium, calcium, strontium, barium, cobalt, nickel, zinc,germanium, niobium, zirconium, molybdenum, tungsten, copper, tellurium,tantalum, selenium, bismuth, cerium, indium, arsenic, boron, aluminum,and manganese, wherein the relative ratios of these elements arerepresented by the following general formula: V₁Sb_(m)A_(a)D_(d)O_(x)wherein A when present is at least one of Ti and Sn, D when present isat least one of Li, Mg, Ca, Sr, Ba, Co, Fe, Cr, Ga Ni, Zn, Ge, Nb, Zr,Mo, W, Cu, Te, Ta, Se, Bi, Ce, In, As, B, Al, and Mn, m is between about0.5 to about 10, a is between 0 to about 10, d is 0 to about 10, and xis determined by the oxidation state of the cations present, wherein thecatalyst is produced in a process comprising (i) forming a catalystprecursor slurry comprising a vanadium containing compound and anantimony containing compound in a liquid solvent medium which comprisesan organic solvent, and (ii) recovering a vanadium antimony oxide fromthe slurry by drying the slurry in order to remove water and organicsolvent.
 8. The catalyst of claim 7 wherein the liquid solvent mediumcomprises 10 to 100 wt % organic solvent.
 9. The catalyst of claim 7wherein the liquid solvent medium comprises 50 to 100 wt % organicsolvent.
 10. The catalyst of claim 7 wherein the liquid solvent mediumcomprises 80 to 100 wt % organic solvent.
 11. The catalyst of claim 7wherein the organic solvent comprises at least one organic compoundselected from the group, consisting of alcohols, nitrites, carboxylicacids, amines, and sulfides.
 12. The catalyst of claim 7, wherein thecatalyst comprises vanadium, antimony, iron, at least one of tin,titanium, chromium and gallium, and at least one other promoter elementselected from the group consisting of lithium, magnesium, sodium,calcium, strontium, barium, cobalt, chromium, gallium, nickel, zinc,germanium, zirconium, tantalum, bismuth, cerium, indium, boron,aluminum, and manganese, optionally one or more of molybdenum, tungstenand niobium, and optionally one or more of arsenic, tellurium andselenium, wherein the relative proportions of these elements arerepresented by the following formula:V₁Sb_(b)A_(c)Fe_(d)D_(e)Q_(f)R_(g)O_(x) where A is at least one of Ti,Sn, Cr, and Ga D is at least one of Li, Mg, Ca, Sr, Ba, Co, Ni, Zn, Ge,Zr, Cu, Ta, Bi, Ce, In, B, Al and Mn Q is selected from the groupconsisting of Mo, W, Nb, R is selected from the group consisting of As,Te, Se, and 0.8≦b≦4, 0.01≦c≦2, 0.01≦d≦2, 0≦e≦2, 0≦f<0.01, 0≦g<0.1, and xis determined by the oxidation state of the cations present.
 13. Aprocess for the manufacture of acrylonitrile from a hydrocarbon selectedfrom the group consisting of propylene, propane and mixtures thereofcomprising reacting the hydrocarbon with ammonia and oxygen in thepresence of a vanadium antimony oxide catalyst comprising vanadium,antimony, iron, at least one of tin, titanium, chromium and gallium, andat least one other promoter element selected from the group consistingof lithium, magnesium, sodium, calcium, strontium, barium, cobalt,chromium, gallium, nickel, zinc, germanium, zirconium, tantalum,bismuth, cerium, indium, boron, aluminum, and manganese, optionally oneor more of molybdenum, tungsten and niobium, and optionally one or moreof arsenic, tellurium and selenium, wherein the relative proportions ofthese elements are represented by the following formula:V₁Sb_(m)A_(a)D_(d)O_(x) wherein A when present is at least one of Ti andSn, D when present is at least one of Li, Mg, Ca, Sr, Ba, Co, Fe, Cr, GaNi, Zn, Ge, Nb, Zr, Mo, W, Cu, Te, Ta, Se, Bi, Ce, In, As, B, Al and Mn,m is between about 0.5 to about 10, a is between 0 to about 10, d is 0to about 10, and x is determined by the oxidation state of the cationspresent, wherein the catalyst is produced in a process comprising (i)forming a catalyst precursor slurry comprising a vanadium containingcompound and an antimony containing compound in a liquid solvent mediumwhich comprises an organic solvent, and (ii) recovering a vanadiumantimony oxide from the slurry by drying the slurry in order to removewater and organic solvent.
 14. The process of claim 13 wherein theliquid solvent medium comprises 10 to 100 wt % organic solvent.
 15. Theprocess of claim 13 wherein the liquid solvent medium comprises 50 to100 wt % organic solvent.
 16. The process of claim 13 wherein the liquidsolvent medium comprises 80 to 100 wt % organic solvent.
 17. The processof claim 13 wherein the organic solvent comprises at least one organiccompound selected from the group, consisting of alcohols, nitriles,carboxylic acids, amines, and sulfides.
 18. The process of claim 13,wherein the catalyst comprises vanadium, antimony, iron, at least one oftin, titanium, chromium and gallium, and at least one other promoterelement selected from the group consisting of lithium, magnesium,sodium, calcium, strontium, barium, cobalt, chromium, gallium, nickel,zinc, germanium, zirconium, tantalum, bismuth, cerium, indium, boron,aluminum, and manganese, optionally one or more of molybdenum, tungstenand niobium, and optionally one or more of arsenic, tellurium andselenium, wherein the relative proportions of these elements arerepresented by the following formula:V₁Sb_(b)A_(c)Fe_(d)D_(e)Q_(f)R_(g)O_(x) where A is at least one of Ti,Sn, Cr, and Ga D is at least one of Li, Mg, Ca, Sr, Ba, Co, Ni, Zn, Ge,Zr, Cu, Ta, Bi, Ce, In, B, Al and Mn Q is selected from the groupconsisting of Mo, W, Nb, R is selected from the group consisting of As,Te, Se, and 0.8≦b≦4, 0.01≦c≦2, 0.01≦d≦2, 0≦e≦2, 0>f<0.01, 0≦g<0.1, and xis determined by the oxidation state of the cations present.